cast to void *' from smaller integer type 'int

Pd = Pa; Similarly, Pc may be type cast to type int and assigned the value Pa. 1. As Ferruccio said, int must be replaced with intptr_t to make the program meaningful. There's no proper way to cast this to int in general case. @Xax: Here's a fixed version, without the race condition: gist.github.com/depp/241d6f839b799042c409, gist.github.com/depp/3f04508a88a114734195, How Intuit democratizes AI development across teams through reusability. Find centralized, trusted content and collaborate around the technologies you use most. How to use Slater Type Orbitals as a basis functions in matrix method correctly? int, bigint, smallint, and tinyint (Transact-SQL) - SQL Server You could use this code, and it would do the same thing as casting ptr to (char*). I get the error: "cast to smaller integer type 'int' from 'string' (aka 'char *')" referencing line of code: while (isalpha(residents[i].name) == 0), How Intuit democratizes AI development across teams through reusability. rev2023.3.3.43278. Yesterday, I updated Xcode to the newest version (5.1 (5B130a)) to compatible with iOS 7.1. Windows has 32 bit long only on 64 bit as well. Euler: A baby on his lap, a cat on his back thats how he wrote his immortal works (origin? Casting type int to const void* - C / C++ Sign in Making statements based on opinion; back them up with references or personal experience. On many systems, an 8-bit unsigned int can be stored at any address while an unsigned 32-bit int must be aligned on an address that is a multiple of 4. Find centralized, trusted content and collaborate around the technologies you use most. Using an integer address (like &x) is probably wrong, indeed each modification you will execute on x will affect the pass behaviour. To be honest, I think, clang is too restrictive here. Why does Mister Mxyzptlk need to have a weakness in the comics? What can a lawyer do if the client wants him to be acquitted of everything despite serious evidence? C - Type Casting - tutorialspoint.com No sense in writing a few dozen lines of extra code just to get a bunch of numbered threads. I don't see how anything bad can happen . [mst-vhost:vhost 5/52] drivers/block/virtio_blk.c:539:21: warning What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? GitHub Skip to content Product Solutions Open Source Pricing Sign in Sign up smadaminov / ovs-dpdk-meson-issues Public Notifications Fork 1 Star 1 Code Issues 66 Pull requests Actions Projects 1 Security Insights New issue The pointer doesn't actually point to anything, but it's the result of an earlier cast from an integer to a pointer (e.g. This is not even remotely "the correct answer". You use the address-of operator & to do that. What is the correct method to cast an int to a void*? STR34-C. Cast characters to unsigned char before converting to larger On a 64-bit Windows computer, 'long' is a 32-bit type, and all pointers are 64-bit types. FAILED: lib/libopenvswitch.a.p/odp-util.c.obj However even though their types are different, the address is going to be the same. What does it mean to convert int to void* or vice versa? What is the purpose of non-series Shimano components? Converting a pointer to an integer whose result cannot represented in the integer type is undefined behavior is C and prohibited in C++. "I think what you should do is actually pass the address of the variable to the function" Not necessarily. Not the answer you're looking for? For the remaining integral types, the result is the value of the enum if it can be represented by the target type and unspecified otherwise. In this case, casting the pointer back to an integer is meaningless, because . From what I read about casting in the C11 standard, my feeling is, that it is arguable to emit a warning on an explicit conversion. Using indicator constraint with two variables. Casting int to void* : r/C_Programming - reddit By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Type conversions - cplusplus.com Is it plausible for constructed languages to be used to affect thought and control or mold people towards desired outcomes? A nit: in your version, the cast to void * is unnecessary. Typecasting - Data Types - Language Basics - MQL4 Reference An open (void) pointer can hold a pointer of any type. Don't pass your int as a void*, pass a int* to your int, so you can cast the void* to an int* and copy the dereferenced pointer to your int. Find centralized, trusted content and collaborate around the technologies you use most. Clang warnings for an invalid casting? - The FreeBSD Forums For the Nozomi from Shinagawa to Osaka, say on a Saturday afternoon, would tickets/seats typically be available - or would you need to book? I need to convert the argument to an int for later use: The compiler (GCC version 4.2.4) returns the error: You can cast it to an intptr_t type. What is the difference between const int*, const int * const, and int const *? Making statements based on opinion; back them up with references or personal experience. Even if you are compiling your program for a 32-bit computer, you should fix your code to remove these warnings, to ensure your code is easily portable to 64-bit. To access the object value, use the * dereference operator: int * p; assert (p == null ); p = new int (5); assert (p != null ); assert (*p == 5); (*p)++; assert (*p == 6); If a pointer contains a null value, it is not pointing to a valid object. SCAN_PUT(ATTR, NULL); Is it plausible for constructed languages to be used to affect thought and control or mold people towards desired outcomes? Thanks for contributing an answer to Stack Overflow! Why do academics stay as adjuncts for years rather than move around? I recall there was a TreeNode(int) early on prior to 1.0 release I can't remember why I removed it, if I should felt it was easy enough to cast to (void*) or if it was because it created type inference conflict at the call site. So,solution #3 works just fine. vegan) just to try it, does this inconvenience the caterers and staff? Such a downcast makes no runtime checks to ensure that the object's runtime type is actually D, and may only be used safely if this precondition is guaranteed by other means, such as when implementing static polymorphism. If the original type is a void *, converting to an int may lose date on platforms where sizeof(void *) != sizeof(int) (which is true of LP64 programming model). Casting Pointers - IBM warning C4311: 'type cast': pointer truncation from 'void *' to 'long' in ECPG test files. ../lib/odp-util.c:5601:9: note: expanded from macro 'SCAN_PUT' What happens if you typecast as unsigned first? to the original pointer: The following type designates an unsigned integer type with the Asking for help, clarification, or responding to other answers. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Types - D Programming Language Mutually exclusive execution using std::atomic? In 64-bit programs, the size of the pointer is 64 bits, and cannot be put into the int type, which remains 32-bit in almost all systems. However, you are also casting the result of this operation to (void*). ../lib/odp-util.c:5603:13: note: expanded from macro 'SCAN_PUT' And in the function you get the value of the pointer by using the dereference operator *: Please read why glib provide macros for this kind of conversions, there's no need to repeat the text here. Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2. what does it mean to convert int to void* or vice versa? */void **MatrixIB (unsigned long x, unsigned long y, int size){ void *ptr; void **returnPtr; register unsigned long i, j; Bulk update symbol size units from mm to map units in rule-based symbology. If int is no larger than pointer to void then one way to store the value is by simply copying the bytes: int i . Half your pointer will be garbage. How to correctly cast a pointer to int in a 64-bit application? You can fix this error by replacing this line of code. If you are going to pass the address you typically need to exert some more control over the lifetime of the object. Once you manage to make this cast, then what?! How to notate a grace note at the start of a bar with lilypond? This method will not work on 64 bit Big Endian platform, so it unnecessarily breaks portability. Cast Operations - Oracle I personally upvoted this answer because by it's first line of text it helped me to understand the reason of this strange error message and what am I, poor idiot, doing :D. Not valid on Windows 64 - long is still 32-bit but pointers are 64-bit. To learn more, see our tips on writing great answers. Implementing From will result in the Into implementation but not vice-versa. What I am trying to do in that line of code is check to make sure each character in my string is alphabetical. Not the answer you're looking for? How can this new ban on drag possibly be considered constitutional? Here, the Java first converts the int type data into the double type. A sane compiler may throw a warning on lines like this but by no way it should throw an error, because this code is NOT wrong, it is just potentially error-prone, but can be perfectly valid. Replacing broken pins/legs on a DIP IC package, How to handle a hobby that makes income in US. Connect and share knowledge within a single location that is structured and easy to search. Type Casting in C Language with Examples - Dot Net Tutorials I am an entry level C programmer. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Just re-enforcing the old behavior of Xcode 5.0 and earlier versions, that already cut away parts of the address by casting it to int, won't introduce any new bugs and avoids the need to learn and understand lots of implementation-internal cocos code. Typically, long or unsigned long is . If the function had the correct signature you would not need to cast it explicitly. to your account, [87/252] Compiling C object lib/libopenvswitch.a.p/odp-util.c.obj Get the address of a callback function to call dynamically in C++, error: call of overloaded function ambiguous, error: cast from to unsigned int loses precision [-fpermissive]. My code is GPL licensed, can I issue a license to have my code be distributed in a specific MIT licensed project? Not the answer you're looking for? It was derived from the BCPL, and the name of the b language is possibly from the BCPL contraction. Getting Command /bin/sh failed with exit code 65 Error with Xcode 5.1 . Does melting sea ices rises global sea level? Projects. Compile error on Android ARM Issue #163 cisco/ChezScheme How to correctly cast a pointer to int in a 64-bit application? Hence there is no loss in data. a cast of which the programmer should be aware of what (s)he is doing. To avoid truncating your pointer, cast it to a type of identical size. This is known as implicit type casting or type promotion, compiler automatically converts smaller data type to larger data type. Just edited. and how to print the thread id of 2d array argument? equal to the original pointer: First you are using a define, which is not a variable. This allows you to reinterpret the void * as an int. converted back to pointer to void, and the result will compare equal Unless you have a valid address at that value, you are going to invoke undefined behaviour when try to use that pointer. And then assign it to the double variable. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. cast to 'void *' from smaller integer type 'int' On all of them int is 32bit, not 16bit. Wrong. error: comparison between pointer and integer ('int' and 'string' (aka 'char *')), CS50 Caesar program is working but check50 says it isn't. Did i have to face to unexpected runtime issues, i guess not, i've found another discussion on this -. Put your define inside a bracket: #define M_TABLE_SIZE (64*1024) Now, you can do: static const void* M_OFFSET = (void*) M_TABLE_SIZE; without a problem. lexborisov Modest Public. c - Cast int to void* - Stack Overflow Such pointers can be stored in 32-bit data types (for instance, int, DWORD). It is commonly called a pointer to T and its type is T*. void* -> integer -> void* rather than integer -> void* -> integer. c - How to cast an integer to void pointer? - Stack Overflow This example is noncompliant on an implementation where pointers are 64 bits and unsigned integers are 32 bits because the result of converting the 64-bit ptr cannot be represented in the 32-bit integer type. rev2023.3.3.43278. Yeah, the tutorial is doing it wrong. If it's anything like cocos2d-iphone v2.x and just based on this slice of code in a core class I wager it's safe to say that cocos2d-x 2.x also is not compatible with 64 bit code, and you can expect all kinds of issues (not just compile-time but also runtime). Is a PhD visitor considered as a visiting scholar. Asking for help, clarification, or responding to other answers. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. The code ((void*)ptr + 1) does not work, because the compiler has no idea what size "void" is, and therefore doesn't know how many bytes to add. There is absolutely not gurantee that sizeof(int) <= sizeof(void*). You need to pass an actual pointer. What can a lawyer do if the client wants him to be acquitted of everything despite serious evidence? The cast back to int * is not, though. Why is there a voltage on my HDMI and coaxial cables? Any help with this is appreciated. whether it was an actual problem is a different matter though. I'm trying to learn pthreads and thing that keeps bugging me is how do i really pass argument to the function. My code is GPL licensed, can I issue a license to have my code be distributed in a specific MIT licensed project? This solution is in accordance with INT18-C. So you could do this: Note: As sbi points out this would require a change on the OP call to create the thread. But you seem to suggest by your answer that the user can pass 5 to pthread_create and then perform the above cast to get it back. The compiler issues the "cast from integer to pointer of different size" warning whenever the value of an integer is converted to a pointer, especially when the memory allocated to a pointer is smaller than the memory allocated to an integer data type. The problem is not with casting, but with the target type loosing half of the pointer. Thanks for contributing an answer to Stack Overflow! If your standard library (even if it is not C99) happens to provide these types - use them. How to convert a factor to integer\numeric without loss of information? Why do small African island nations perform better than African continental nations, considering democracy and human development? It is easier to understand and write than any other assembly language. @kshegunov said in Number Type Cast: const void * x; int y = int (x); compiles just fine. If the value is ever used as pointer again that will prove to be an extremely bad idea. : iPhone Retina 4-inch 64-bit) is selected. Then i can continue compiling. Why is this sentence from The Great Gatsby grammatical? If any, how can the original function works without errors if we just ignore the warning. You need to cast the void* pointer to a char* pointer - and then dereference that char* pointer to give you the char that it points to! rev2023.3.3.43278. Please unaccept the answer you have chosen as it is wrong (as the comments below it say) and will lead to bugs. pthread create managing values generated in function (in c), Establishing TCP socket connection between PHP client and C server on Ubuntu. Based on the design of this function, which modification is right. Then I build my project, I get the error "Cast from pointer to smaller type 'int' loses information" in EAGLView.mm file (line 408) when 64-bit simulators (e.g. I need to cast the int from the first function so that I can use it as an argument for the second function. Use returnPtr[j] = (void *) ((long)ptr + i); ). Most answers just try to extract 32 useless bits out of the argument. ^~~~~~~~~~~~~~~~~~~~~ what happens when we typecast normal variable to void* or any pointer variable? There's no proper way to cast this to int in general case. Thank you all for your feedback. And when assigning to a void pointer, all type information is lost. I have the following function and when I compile it under VS.NET 2005, the following compile warnings show up: Warning1warning C4311: 'type cast' : pointer truncation from 'void *' to 'long'c:\temp\testone\lib\utils.c56Warning2warning C4312: 'type cast' : conversion from 'unsigned long' to 'void *' of greater sizec:\temp\testone\lib\utils.c56, Code Snippet "After the incident", I started to be more careful not to trip over things. Fork 63. A nit: in your version, the cast to void * is unnecessary. Cerror: cast to 'void *' from smaller integer type 'int' Error while setting app icon and launch image in xcode 5.1. To learn more, see our tips on writing great answers. I'm only guessing here, but I think what you are supposed to do is actually pass the address of the variable to the function.

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